1. Field of the Invention
The invention relates to a rotatory-working oil separator that purifies the crankcase breather gases of an internal combustion engine.
2. Prior Art
Oil droplets and oil aerosols are a part of the blow-by gases from the crankcase breather of all internal combustion engines. When introducing these gases that contain oil into the suction area of the motor, fouling occurs in the subsequent components, which has a negative effect on the functioning of the motor components. The oil that was carried along must therefore be removed from the crankcase breather gas.
Usually, the oil separation from the crankcase gases occurs with the help of separators that consist of a texture of fibers or with the help of ray deflections on deflecting plates or a combination of these processes. In addition, superfine filters are used, which however work with a high differential pressure.
Cyclone separators need a relatively large installation space and, conditional upon principle, only work optimally in an operating point
Electrostatic filters require an additional electrical input and are relatively cost intensive. Moreover, these filters can not be used with combustible gases. Rotatory-working oil separators, in which the oil droplets are spun out with the help of impellers, are also known. They are mostly run with electric motors, air pressure turbines or oil pressure turbines.
The optimal design of the oil separator usually used causes considerable problems because the degree of oil separation and the differential pressure that appears depend on the oil content, the oil temperature, the droplet size distribution, the blow-by flow of gas, the pulsating current, the engine revolutions and the engine stress, and from the sudden revolution and stress changes etc. Therefore, plenum chambers and preliminary filter are still inserted in front of the actual oil separators. These require additional room and cause additional costs. Further cost results still from the oil container, the return valve and the oil return line to the engine""s oil sump.
A fume separator mechanism is known from DE 43 30 912 A1, by which a body of rotation is furnished with a filter filling. Fume-forming particles should be hydroextracted by the body of rotation through the effect of centrifugal force in the radial direction. This fume separator mechanism requires however a reservoir and deflecting ribs for the fume-forming particles and is thus not suitable for the purification of blow-by gases. Furthermore, the body of rotation is arranged together with the driving motor inside the housing. This leads to the large dimensions of the fume separator mechanism.
A purifying apparatus is known from DE 196 37 431 A1, by which an air current with particulate solids is guided through a rotating perforated disk. The particulate solids should be seized by the perforated disk and radially spun outward. This purifying apparatus is however not suitable for the separation of liquid materials such as oil droplets or oil aerosols from the air.
The invention is based on the task of creating an oil separator that can guarantee a nearly complete oil separation from the crankcase breather gases under all operating conditions that can occur and at low differential pressure, and in doing so can be produced at low cost.
This task is accomplished with an oil separator as described herein.
Through this, a filter disk is fastened to a shaft in the crankcase in such a way that the crankcase gases must pass through the filter disk. The oil and soot particles separated on the surface and on the way through the filter disk are spun off through the rotating disk and remain in the crankcase so that no oil collection area and no special oil return is necessary. The self-purifying ability of the rotating filter disk is so great that the differential pressure of the filter also does not substantially change during long running times.
Further features and advantages relating to the invention are described in the specification and drawing.
Oil separators for use in crankcase breathers of an internal combustion engine, which has a filter disk for the flow of gases to be purified, are especially cost-efficient if the filter disk according to an embodiment of the invention is fitted to a camshaft, a differential shaft or a crankshaft of an internal combustion engine. Through this, an oil separator according to an embodiment of the invention does not require any expensive power unit since at least one of the shafts mentioned is present in internal combustion engines anyway.
An especially advantageous use of a rotary filter disk for the flow of gases to be purified is the separation of oil droplets and oil aerosols from gases of a crankcase breather of an internal combustion engine. Such a filter disk can withstand the changing load conditions of the internal combustion engine and can clean itself for a long time. Thus the separation of oil droplets and oil aerosols from the gases of the crankcase breather is nearly maintenance-free. Soot particles are also spun off by the filter disk.